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><H1
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><A
NAME="CHKPASS"
>F.6. chkpass</A
></H1
><P
>  This module implements a data type <TT
CLASS="TYPE"
>chkpass</TT
> that is
  designed for storing encrypted passwords.
  Each password is automatically converted to encrypted form upon entry,
  and is always stored encrypted.  To compare, simply compare against a clear
  text password and the comparison function will encrypt it before comparing.
 </P
><P
>  There are provisions in the code to report an error if the password is
  determined to be easily crackable.  However, this is currently just
  a stub that does nothing.
 </P
><P
>  If you precede an input string with a colon, it is assumed to be an
  already-encrypted password, and is stored without further encryption.
  This allows entry of previously-encrypted passwords.
 </P
><P
>  On output, a colon is prepended.  This makes it possible to dump and reload
  passwords without re-encrypting them.  If you want the encrypted password
  without the colon then use the <CODE
CLASS="FUNCTION"
>raw()</CODE
> function.
  This allows you to use the
  type with things like Apache's <TT
CLASS="LITERAL"
>Auth_PostgreSQL</TT
> module.
 </P
><P
>  The encryption uses the standard Unix function <CODE
CLASS="FUNCTION"
>crypt()</CODE
>,
  and so it suffers
  from all the usual limitations of that function; notably that only the
  first eight characters of a password are considered.
 </P
><P
>  Note that the <TT
CLASS="TYPE"
>chkpass</TT
> data type is not indexable.
  
 </P
><P
>  Sample usage:
 </P
><PRE
CLASS="PROGRAMLISTING"
>test=# create table test (p chkpass);
CREATE TABLE
test=# insert into test values ('hello');
INSERT 0 1
test=# select * from test;
       p
----------------
 :dVGkpXdOrE3ko
(1 row)

test=# select raw(p) from test;
      raw
---------------
 dVGkpXdOrE3ko
(1 row)

test=# select p = 'hello' from test;
 ?column?
----------
 t
(1 row)

test=# select p = 'goodbye' from test;
 ?column?
----------
 f
(1 row)</PRE
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><H2
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><A
NAME="AEN130378"
>F.6.1. Author</A
></H2
><P
>   D'Arcy J.M. Cain (<CODE
CLASS="EMAIL"
>&#60;<A
HREF="mailto:darcy@druid.net"
>darcy@druid.net</A
>&#62;</CODE
>)
  </P
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